Stealthy loop material for hook and loop fastener

ABSTRACT

A loop material for a hook and loop fastener, which has ink jet printing on a face of the loop material, wherein the loop material has a shear strength of at least 10 pounds per square inch as measured by ASTM D-5169 and a peel strength of at least 1 pound as measured by ASTM D-5170. The printing on the face of the loop material substantially reduces the sound level associated with disengagement of the loop material from a hook material. A process for preparing the loop material is also disclosed.

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention relates to an improved loop material for hook and loop fasteners, and more particularly to a loop material printed with graphics and/or capable of disengaging relatively quietly. The invention further relates to a method of producing such a loop material and to hook and loop fasteners comprising same.

2. Description of Related Art

Camouflage clothing is commonly used in combat and hunting situations. Camouflage uniforms and equipment (e.g., load carriage and tactical vests) presently employed by the U S military can have large areas of solid color loop material applied to the external surfaces thereof. These areas of loop material are used for functional reasons, including the placement of rank tabs and as closures such as at the wrist and ankle. However, these solid color patches are easily visible even at a distance to the naked eye, and thus degrade the stealthiness of the camouflage uniforms and equipment.

Further, in nighttime conditions, the current camouflage printed fabrics have near infrared reflective capability such that when the soldier outfitted in the camouflage printed combat uniform and equipment items is viewed through night vision image enhancing devices they are not easily detectable against the vegetation and other elements in the environment. However, the solid color patches of loop material are readily detectable, even if the loop material itself is designed to have near infrared reflectance, as the patches stand out against the more detailed and smaller scale camouflage print patterns of the uniforms and equipment.

The aforementioned deficiencies of existing loop materials employed by the military present a potential threat to the safety of soldiers in day or night combat.

Printed loop materials are known in the art. For example, U.S. Pat. No. 7,325,421 and U.S. Pat. No. 6,910,353 disclose printed loop fabrics said to possess improved graphic visibility and clarity. Although these patents assert that the graphic can be applied to the face or to the back side of the loop fabric by any of a variety of known printing techniques, only flexographic printing is exemplified, with the engagement strength of printed loop fabrics tested only for embodiments having flexographic printing applied to the back side of the fabrics.

It is accordingly desired to provide a loop material printed on its face with a camouflage design. It is further desired that the printing on the loop material does not unduly weaken the engagement strength of the loop material. It is still further desired that the loop material disengages relatively silently from a complementary hook material.

All references cited herein are incorporated herein by reference in their entireties.

BRIEF SUMMARY OF THE INVENTION

A first aspect of the invention comprises a loop material for a hook and loop fastener, said loop material having ink jet printing (also known as digital textile printing or digital ink jet printing) on a face of the loop material, wherein the loop material has a shear strength of at least 10 pounds per square inch as measured by ASTM D-5169 and a peel strength of at least 1 pound as measured by ASTM D-5170.

A second aspect of the invention comprises a camouflage garment comprising the inventive loop material applied to a substrate garment bearing a camouflage design, wherein the ink jet printing on the face of the loop material is identical to the camouflage design of the substrate garment such that the loop material blends into the background of the substrate garment in the visible range and in the near infrared range of the light spectrum.

A third aspect of the invention comprises military, law enforcement, hunting and/or tactical gear comprising the inventive loop material applied to substrate gear bearing a camouflage design, wherein the ink jet printing on the face of the loop material is identical to the camouflage design on the substrate gear such that the loop material blends into the background of the substrate gear in the visible range and in the near infrared range of the light spectrum.

A fourth aspect of the invention comprises a fastener comprising the inventive loop material and a hook material.

A fifth aspect of the invention comprises a method for making the inventive loop material for a hook and loop fastener, said method comprising: (a) providing a basic loop material; and (b) ink jet printing on a face of the basic loop material to provide the inventive loop material, wherein the method is conducted without attaching the loop material to a frame.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

The invention will be described in conjunction with the following drawings, wherein:

FIG. 1 is a photograph of a prior art loop material bonded to a military garment;

FIG. 2 is a photograph of an embodiment of the inventive loop material bonded to a military garment; and

FIG. 3 is a bar graph showing the reduced disengagement noise of an embodiment of the inventive loop material relative to that of a prior art loop material.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

The invention addresses problems associated with prior art loop materials by providing a loop material having ink jet printing on the face of the fabric. The loop material is adapted to engage and disengage a complementary hook fabric (or material) with an engagement strength adequate to function cooperatively with the hook fabric as a fastener.

The loop material is preferably a weft knit fabric. However, it is also contemplated that the loop material can be, e.g., a warp knit fabric, or a woven fabric, a non-woven (e.g., spun-bonded) fabric, or a polymeric material in less preferred embodiments. Commercially available loop materials marketed by Milco Industries of Bloomsburg, PA, USA (Styles 44901 and 44950, which are weft knit nylon based loop materials) and Gehring Textiles Inc. of Garden City, N.Y., USA (Style WW991/1, which is a napped monofilament 100% nylon warp knit) have proven to be acceptable as basic loop materials (i.e., a loop material, which can be modified in accordance with the present invention to provide the inventive loop material). Other suitable basic loop materials include but are not limited to loop materials disclosed in the following patents: U.S. Pat. No. 4,931,343, U.S. Pat. No. 5,267,453, U.S. Pat. No. 5,326,612, U.S. Pat. No. 6,096,667, U.S. Pat. No. 6,099,932, U.S. Pat. No. 6,216,496, U.S. Pat. No. 6,854,297, U.S. Pat. No. 6,845,639, U.S. Pat. No. 7,207,195, U.S. Pat. No. 7,547,469, and U.S. Pat. No. 7,960,008.

It is contemplated that a variety of yarns may be suitable for use in the loop material. Yams of the loop material can be multifilament and/or monofilament yarns of natural and/or synthetic substances. Yarns of synthetic substances, such as, e.g., polyester, polypropylene and especially nylon yarns, are preferred.

The denier of the yams may vary depending upon the desired weight of the loop material per unit fabric dimension (ounces per square yard or osy). Suitable deniers include but are not limited to Nylon filaments from 70 to 200 denier. The loop material preferably has a weight of 2-16 osy, more preferably about 8 osy.

The loop material is dyed or undyed, depending on the colors in the printing to be applied to the face of the loop material.

The loop material is preferably backcoated with a suitable backcoating applied to the back side of the loop material. It is preferred to use an acrylic for backcoating. Other suitable backcoatings include but are not limited to latex and polyurethane. Backcoating can be applied before or after printing.

The loop material is preferably napped before printing.

The thickness of the loop material after printing is preferably at least 0.01 in., or at least 0.05 in., or at least 0.1 in., or at least 0.5 in. The maximum thickness of the loop material is preferably less than 1 in., or less than 0.5 in., or less than 0.1 in., or 0.5-0.9 in.

In embodiments of the invention intended to blend in with a pattern printed on an underlying substrate on which the loop material is bonded, the loop material is printed with a pattern that blends in with the underlying substrate pattern. Most preferably, the printed pattern is a camouflage design. Camouflage designs for military and hunting use typically include 2 or 3 or 4 or more colors in a variety of patterns. Thus, preferred embodiments of the inventive loop material are printed with a pattern or design comprising at least four distinct colors. More preferably, the loop material is printed with a camouflage design on its face (i.e., the hook receiving area), which is substantially the same design used on substrate fabrics (e.g., military uniforms) on which the loop material is applied. Compare FIG. 1, which shows a solid color loop material of the prior art bonded to a camouflage garment, with FIG. 2, which shows a camouflage printed loop material of the invention bonded to a camouflage garment. Suitable camouflage patterns include but are not limited to Universal Camouflage Pattern, MultiCam, Navy Working Uniform, MARPAT-Woodland, MARPAT-Desert, Advanced Tactical Assault Camouflage, Three-Color Desert, U.S. Woodland, Kryptek, Real Tree, Mossy Oak, Ghostex, Orion Designs and Penncott.

While others, such as Sasser et al. in U.S. Pat. No. 7,325,421 and U.S. Pat. No. 6,910,353, purport to have successfully printed multicolored patterns on the face of loop material, the inventor has discovered means for providing good quality patterns on the face of the loop material without unduly impairing the physical performance of the loop material. In particular, the invention enables the provision of face-printed loop material without unduly sacrificing the engagement strength of the basic loop materials from which the final product is made. In addition, the quality of the printing on the loop material face is sufficiently good such that the loop material is difficult to distinguish from an underlying substrate material on which it is bonded, such as a military uniform, military gear, hunting apparel, hunting gear, and the like. Thus, the inventive loop material preferably provides enhanced concealment in the visible and near infrared spectrum in precisely the same camouflage design as used on the combat uniform and equipment worn and carried by a soldier.

Loop material of the invention exhibits engagement strength adequate for most applications. This performance compatibility can be measured by testing. Two well-established test methods measure the strength of engagement between hook and loop materials. The first is commonly known as Shear Strength Testing (ASTM D-5169) and the second as Peel Strength testing (ASTM D-5170). All references herein to shear strength and peel strength are as measured by these testing standards.

Loop materials of the invention preferably meet current US military standards for shear strength and peel strength. These standards are defined in A-A-55126B dated 7 Sep. 2006. The US military requirement for shear strength is a minimum strength of 10 pounds per square inch (psi). Preferred embodiments of the invention have a shear strength of at least 10 psi or at least 15 psi or 10-20 psi. The US military requirement for peel strength is a minimum strength of 1 pound per inch. Preferred embodiments of the invention have a peel strength of at least 1 pound per inch or at least 1.5 pounds per inch or 1-2 pounds per inch.

It is also preferred that the loop materials of the invention possess color fastness to crocking, dry cleaning, light and laundering to at least the same extent as substrate fabrics to which the loop materials are to be bonded.

Moreover, preferred embodiments of the loop material of the invention unexpectedly possess an ability to disengage from a complementary hook material substantially more quietly than basic (e.g., conventional) loop materials. While patents such as U.S. Pat. No. 4,884,323, U.S. Pat. No. 4,776,068 and U.S. Pat. No. 7,475,455 purport to address the issue of disengagement noise associated with hook and loop fasteners, they do not do so in the context of providing face-printed loop materials, and do not at all suggest that face-printing itself can reduce disengagement noise.

In preferred embodiments of the invention, the loop material will, during disengagement from a complementary hook material, exhibit a sound level which is reduced by 3 dB or 6 dB or 9 dB or 12 dB or 15 dB or 18 dB relative to the basic loop material from which it is produced. (All sound level values in dB referenced herein are to be measured by a sound level meter, which complies with IEC 61672:2003 and has a microphone placed 1 foot from a hook and loop fastener, which is separated at a separation rate of about 4-6 inches/second, wherein the fastener consists of conventional 1 in.×5 in. hook material joined to a 5 in.×6 in. patch of loop material stitched to a 50% cotton/50% nylon substrate fabric.) It is further preferred that the loop material is adapted to exhibit such a “disengagement sound level” of less than 70 dB or less than 67 dB or less than 64 dB or less than 61 dB or less than 58 dB or less than 55 dB or less than 52 dB during disengagement from a complementary hook material. In certain embodiments, the peak disengagement sound level will be 52 dB to 70 dB, or 55 dB to 67 dB.

A method for providing loop materials is an additional aspect of the invention. The method comprises providing a basic loop material and printing ink or dye on the face of the basic loop material to provide the inventive loop material.

Not all types of printing are suitable for use in the invention. It was unexpectedly found, for example, that ink jet printing is much preferred to other forms of printing. Non-ink jet printing, such as galvano screen printing, also known as wet printing, was capable of rendering designs on the face of loop material, which were satisfactory from a visual performance perspective. However, it was unexpectedly discovered that the framing of the loop material, which is necessary to wet printing techniques, results in undue shrinkage of the loop material, measured by AATCC 135 Option 3, V, Aiii test method for Dimensional Stability. Wet printed loop materials have exhibited dimensional stability in the 8% range in the warp, while ink jet printed loop materials have been able to consistently achieve results of 3% shrinkage or less in the warp and fill.

Further, it was also found that non-ink jet printing, such as wet printing and/or transfer printing, resulted in shear results that were not consistently equal to or greater than 10 psi and in peel results that were not consistently equal to or greater than 1 pound per inch, which resulted in an unacceptable product.

Thus, a particularly preferred embodiment of the invention comprises ink jet printing on the face of the loop material and subsequently conducting a post-printing wash cycle. Ink jet printing does not require a frame, so there is no chance of stretching the fabric out during the printing and finishing process. The additional step of post-printing washing facilitates the provision of shrinkage not exceeding about 3%. This post printing cycle was at 60° C. with the ink jet printed loop fabric immersed for less than two minutes, but other wash temperatures and dwell times are anticipated dependent upon fiber content, denier, thickness and other variables.

Preferred inks for use in the invention include but are not limited to pigment-based inks reactive based inks, dispersed and acid based inks, such as, e.g., Lanaset, Terasil and Lysosphere inks from Huntsman; Jettex RV inks from Dystar; Jacquard Inkjet Fabric Systems' acid, pigment and reactive inks; Artistri pigment and dye-based inks from Dupont; and dispersed inks from Stork Prints BV.

Suitable ink jet printers include but are not limited to MSPrint JPS, Mimaki JV5, Mimaki TX2, Reggaino Dream Machine, MSPrint Lario, Mutoh and Roland.

The inventive loop material of the invention is preferably applied to garments and gear for military and/or hunting use, including but not limited to shirts, vests, jackets, overcoats, pants, shorts, backpacks, duffel bags, body armor vests, belts, holsters, etc. Stitching is the preferred means for attaching the loop material to the underlying substrate material, but other bonding means such as adhesive agents, are also suitable.

The invention will be illustrated in more detail with reference to the following Examples, but it should be understood that the present invention is not deemed to be limited thereto.

EXAMPLES Example 1

MULTICAM camouflage print was ink jet printed on a basic loop material (a weft knit fabric) to provide an inventive loop material. The inventive loop material achieved good visual color match for all the shades in the camouflage design. The color fastness to crocking, dry cleaning and light and laundering were tested. The inventive loop material achieved satisfactory color fastness for all shades in the camouflage design. Further, the breakup through night vision image enhancing devices matched the break up of camouflage printed fabrics, such as the Nylon/Cotton used by the US military for uniforms. The inventive loop material blended into the background of the underlying fabric substrate in the visible range and in the near infrared range of the light spectrum.

Example 2

The invention was tested for its noise level in stand-off testing in which observers in the field recorded when they could hear disengagement of fasteners. Inventive and basic (conventional) loop materials were comparatively tested using conventional hook materials. A 33-37% reduction in detection range was observed when using the inventive loop materials. This was assessed by measuring the distance between the observer and the tester (engaging and disengaging the hook and loop materials, first conventional and then the invention) and recording the difference in distance between hearing the conventional fastener and hearing the fastener comprising the inventive loop material. The results are plotted in FIG. 3, wherein the basic loop material is identified as “baseline” and the inventive loop material is identified as “Sample B”. Disengagement was tested at fast and slow rates.

Accordingly, the invention provides an important advance in the hook and loop fastener art, which will be of great use in combat, law enforcement and hunting situations, where stealth is critical.

While the invention has been described in detail and with reference to specific examples thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. 

What is claimed is:
 1. A loop material for a hook and loop fastener, said loop material having ink jet printing on a face of the loop material, wherein the loop material has a shear strength of at least 10 pounds per square inch as measured by ASTM D-5169 and a peel strength of at least 1 pound per inch as measured by ASTM D-5170.
 2. The loop material of claim 1, having a disengagement sound level of less than 64 dB during disengagement from a complementary hook material.
 3. A camouflage garment comprising the loop material of claim 1 applied to a substrate garment bearing a camouflage design, wherein the ink jet printing on the face of the loop material is identical to the camouflage design of the substrate garment such that the loop material blends into the background of the substrate garment in the visible range and in the near infrared range of the light spectrum.
 4. Military law enforcement, hunting and/or tactical gear comprising the loop material of claim 1 applied to substrate gear bearing a camouflage design, wherein the ink jet printing on the face of the loop material is identical to the camouflage design on the substrate gear such that the loop material blends into the background of the substrate gear in the visible range and in the near infrared range of the light spectrum.
 5. A hook and loop fastener comprising the loop material of claim 1 and a hook material.
 6. A method for making a loop material for a hook and loop fastener, said method comprising: providing a basic loop material; and ink jet printing on a face of the basic loop material to provide the loop material of claim 1, wherein the method is conducted without attaching the loop material on a frame.
 7. The method of claim 6, further comprising washing the loop material to provide the loop material with a shrinkage not exceeding about 3% in a warp or fill direction.
 8. The method of claim 6, wherein the loop material has a disengagement sound level which is reduced by at least 9 dB relative to the basic loop material. 